Background: Recent therapeutic advances in cardiovascular diseases are indebted to the discovery of endothelial progenitor cells (EPC). Nitric oxide (NO) and stromal cell derived factor-1α (SDF-1α) play roles in migration, homing, and differentiation of EPCs in mature endothelial cells. The incidence of cardiovascular diseases is higher in men than women. This fact suggests the influence of sex hormones on the pathophysiology of cardiovascular diseases. Methods: 24 adult female Wistar rats weighing 160–180 grams were randomly divided into four groups (n = 6): 1) sham-treated by sesame oil, 2) ovariectomized (OVX)-treated by sesame oil, 3) OVX-treated by 10 µg/kg/day testosterone, 4) OVX-treated by 100 µg/kg/day testosterone. After 21 days from injection, the animals were euthanized and blood samples were stored for the determination of serum levels of NO and SDF-1α. Findings: The serum levels of NO in sham, OVX, OVX-10 µg/kg/day testosterone, and OVX-100 µg/kg/day testosterone groups were 30.7 ± 1.4, 22.4 ± 0.3, 18.3 ± 1.7, and 19.2 ± 0.4 µmol/L, respectively. Moreover, the corresponding values for the serum level of SDF-1α were 125 ± 42.4, 70.6 ± 10.3, 69.4 ± 15.2, and 166 ± 62 pg/ml. The serum concentration of NO in testosterone treated groups was significantly lower than the other groups (P < 0.05). Nonetheless, there was no significant differences in SDF-1α levels between the study groups (P = 0.6). Conclusion: Totally, this study suggests that testosterone might influence cardiovascular diseases by reducing vascular healing factors such as nitric oxide. Keywords: Testosterone, Nitric oxide, Chemokine CXCL12